JLC Duomètre à Quantième Lunaire 40.5mm vs. 42mm

ED209 · 2012-08-31T15:09:40Z

Explore the JLC Duomètre à Quantième Lunaire 40.5mm pink gold vs. 42mm platinum. Detailed comparison, Caliber 381 insights, and collector opinions.

ED209

WPS member · Jaeger-LeCoultre forum

30 replies6037 views0 photos

ED209's detailed comparison of the Jaeger-LeCoultre Duomètre à Quantième Lunaire in its 40.5mm pink gold iteration against the 42mm platinum Duomètre à Chronographe offers invaluable insights for collectors. His hands-on perspective, complete with high-quality images and video, highlights critical design and wearability differences that might influence purchasing decisions. This piece remains highly relevant for understanding JLC's Duomètre line and its evolution.

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After reading the recent posts from fellow PuristS niterider and moc about the new Duometre a Quantieme Lunaire, I thought I'd share a few more pics and a short video of this watch. On my last visit to the local JLC Boutique I had a chance to compare the newly introduced SIHH 2012 version in 18 carat pink gold versus the standard sized Duometre a Chronograph in platinum.

One of the features that is different between the 40.5mm and the 42mm Duometre a Quantieme Lunaire is the skeletonized dial area near the 5 and 7 o'clock positions. The 40.5mm has a solid dial which makes the two barrel power reserve indicators easier to read, but personally I love skeletonized movements and would have preferred the open dial. But at the same time, I do like the solid dial as it shows off the beautiful grained texture of the dial.

The 18 carat pink gold case is 40.5mm in diameter and the thickness is slightly thinner at 13.07mm compared to the larger Duometre which is 13.5mm thick. The sales rep at the JLC Boutique mentioned that the Duometre a Quantieme Lunaire couldn't be made any thinner because of the movement.

I had a chance to compare the two side by side (sorry, didn't take a pic while I was trying them on) and I felt that the 2mm diameter change made a big difference when worn on my small wrist. One other detail I noticed was that the lugs are slightly smaller which seems to make the 40.5mm Duometre more proportional. As you can probably tell by now, I really liked the smaller 40.5mm size. It still does have an impression of being a larger watch than the 40.5mm specifications and I think this is due to the cambered sapphire glass stretching all the way to the outer edges of the thin bezel.

At the 10 o'clock position is the moon phase and date subdial. The larger blued hand indicates the date, while the slightly shorter gold hands points to the inner concentric subdial to indicate the age of the moon. The full moon cycle is 29 1/2 days (as seen on the lower center numbering on the subdial) and can be corrected using a pusher on the side of the case at the 12 o'clock position.

A 18 carat pink gold push piece at the 10 o'clock side of the case is used to adjust the date, while crown is used to adjust the time hours and minutes.

Movement is the Jaeger LeCoultre Caliber 381 and consists of 367 parts with two independent barrels and 50 hour power reserve. One gear train is for the time and the other is for the calender and jumping seconds hand mechanism.
The movement itself is 33.70mm in diameter and is 7.25mm thick.

Here's a pic of the platinum Duometre a Chronograph that was on display at the boutique (you can see the pink gold version on the lower left of the display case). The larger size and the heftier weight of the platinum case gave me the impression of a much larger watch and presense on the wrist.

And finally here's a short video of the watch. Has anyone else had a chance to see this Duometre in person? Did you like the 40.5mm or the 42mm better?

Regards,
ED-209

Key Points from the Discussion

The original 42mm Duomètre à Quantième Lunaire is preferred by some for its skeletonized power reserve cut-outs, which, despite being harder to read, are considered more aesthetically pleasing and artistic. The unique maroon moon phase color on the original is also a distinguishing feature.
The 40.5mm version features a smoother bezel design compared to the 42mm's sharper, stepped bezel. However, the smaller case size of the 40.5mm Duomètre à Quantième Lunaire can make the Caliber 381 movement appear constrained from the exhibition case back, obscuring some details.
Introducing the same Duomètre model in two different sizes (40.5mm and 42mm) is seen by some as a strategic misstep by JLC, creating an impression of indecision rather than a clear product line extension. This approach is perceived as not fully supporting the Duomètre line's established identity.
The decision to downsize the Duomètre à Quantième Lunaire to 40.5mm while being unable to significantly reduce its thickness (due to the movement's dimensions) results in proportions that feel compromised or 'halfway' for some collectors.
Some collectors express a preference for the larger 42mm case combined with the solid, non-cut dial of the newer 40.5mm version, indicating a desire for a combination of features not currently available.
The repositioning of the time subdial to the right side on both Duomètre versions is a practical improvement, making it easier to read the time when the watch is worn under a sleeve.
Despite owning both, the Lunaire is quietly admitted to be the more elegant of the two Duomètre pieces, though both are highly regarded.

The Discussion

amanico

Aug 31, 2012

I long thought about this question.

I prefer the 42 mm version. To say all, I think the 40, 5 mm is a mistake. The two dimensions give the impression, the feeling that JLC is " waving " between the two case sizes while they only wanted to offer a smaller versons for those who prefer smaller watches. I would have a different opinion if JLC had released the 40, 5 mm for a new Duometre, I am not comfortable with the same model coming in two different sizes. Best, Nicolas

ED209

Sep 2, 2012

The two sizes

Hi NIcholas, Thanks for sharing your thoughts on the two sizes of the Duometres. Do you like the skeletonizing on the dial or having the solid dial? Regards, Ed

amanico

Sep 2, 2012

I like both of the dials. I think the solid dial is much easier than the open one.

Each of them offers a different pereception of the watch, and I love that. Best, Nicolas

Mark in Paris

Sep 1, 2012

Thanks for sharing your illustrated thoughts Ed.

I didn't see the 40.5 version yet but I find strange the downsizing, especially when the proportions are changed. They tried to make it smaller but they couldn't make it a thin as they wanted because of the movement's size. This seems to be done half way. For me, the original version is still the right one (and I like the open dial too) Cheers, Mark

ED209

Sep 2, 2012

The smaller version proportions

Hi Mark, Thanks for checking out the post. I agree with you about the proportions and the thinness of the case due to the movement. It was one of the first questions I asked the JLC rep why they couldn't or didn't make it thinner. It would look more proportional that way. Regards, ED-209

moc

Sep 1, 2012

Not only its smaller...

the bezel is different too,I will post pics when at home.The 40.5 bezel is smoother and does t have the typical sharp step of the regular Duometre case. One thing I like is the solid dial vs the apertures of the regular version. One thing I don t like is the fact that the movement from the back display seems too constrained in the smaller case,the back rim of the case covers part of the blue screws and details and that seems not very nice from a design point of view,the cal 381 shows in all its